In a trickling biological filter, the BOD value of the feed stream is S_0i = 500 mg/l with a feed flow of F = 10³ l/h. The effluent BOD value is desired to be S₀ = 10 mg/l. The following kinetic parameters for the biocatalysts are known: r_m = 20 mg/S/l .h and K_s = 200 mg S/l. The biofilm thickness is L = 0.1 mm. The cross-sectional area of the filter is A = 2 m² , and the biofilm surface area per unit volume of the bed is a = 500 cm² /cm³ . Assume that dissolved oxygen is the rate-limiting substrate and the diffusion coefficient of oxygen is D_O2 = 2 × 10^-5 cm² /s. Determine the required height of the bed. You can assume first-order bioreaction kinetics?

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#Question id: 10537

#Section 6: Plant, Animal and Microbial Biotechnology

Given below some functions of the glutamate receptor-like (GLR) genes. Which one is incorrect?

#Question id: 10538

#Section 6: Plant, Animal and Microbial Biotechnology

Injury to the leaf caused by herbivory activates which types of ion channels?

#Question id: 10539

#Section 6: Plant, Animal and Microbial Biotechnology

All plants releases green-leaf volatiles in response to mechanical damage, this volatile is a mixture of

#Question id: 10540

#Section 6: Plant, Animal and Microbial Biotechnology

The following statements are made regarding volatile compounds of plant;

a) secondary metabolites also fuction in defence mechanism but this is not the volatile compound

b) These volatiles can act as cues for natural enemies of the insect herbivore such as parasitic wasps

c) All plants releases green-leaf volatiles in response to mechanical damage that is a mixture of aldehydes, alcohols, and esters

d) These volatiles attracts natural enemies of the attacking insect herbivores—predators or parasites

Which one of the following options represents a combination of correct statements?

#Question id: 10541

#Section 6: Plant, Animal and Microbial Biotechnology

Green-leaf volatiles act as potent signals,  which of the following option is incorrect about this volatile compound

#Question id: 10542

#Section 6: Plant, Animal and Microbial Biotechnology

Following are certain strategies used by pathogen to attack over the host plant that describe plant-pathogen interactions:

                      I                                                                                             II

A. Necrotrophic pathogens                              i) most of the plant tissue remains alive and only minimal cell damage can be observed, as the pathogens feed on substrates provided by their host

B. Biotrophic pathogens                                 ii) In which the host cells are kept alive as described for biotrophic  Pathogens and followed by a necrotrophic stage, in which the pathogens can cause extensive tissue damage

C. Hemibiotrophic pathogens                         iii) attack their host by secreting cell wall–degrading enzymes or toxins, which eventually kill the affected plant cells, leading to extensive tissue maceration. This dead tissue is then colonized by the pathogens and serves as a food source

Which of the following above combination is correct?